Definitely go Class C as you can take it in a 12t which won’t be much bigger than the 7.5s you will encounter but gives you flexibility. Not sure if I would want to master a clutch and gear box as a novice in a hgv but it’s an option? Perhaps when you have passed your lgv do your car manual, that should then update your lgv to manual too??
spacemanZ10:
Definitely go Class C as you can take it in a 12t which won’t be much bigger than the 7.5s you will encounter but gives you flexibility. Not sure if I would want to master a clutch and gear box as a novice in a hgv but it’s an option? Perhaps when you have passed your lgv do your car manual, that should then update your lgv to manual too??
OP I would have to say cat C as all the others have suggested, in the long run it’d be a far more sensible option 
personally I’d go cat C manual for the challenge and then once passed you’ll not only have manual cat C but expect manual cat B as well
Regards what I’ve quoted though I wouldn’t have thought so, as far as I’m aware lower categories can not upgrade higher categories in any way but vice versa and they can. Sure Rog or Pete will be along with their expert knowledge to straighten us all out for sure though.
UselessForce:
Regards what I’ve quoted though I wouldn’t have thought so, as far as I’m aware lower categories can not upgrade higher categories in any way but vice versa and they can. Sure Rog or Pete will be along with their expert knowledge to straighten us all out for sure though.
Manual B can upgrade auto C etc to manual
Manual C can upgrade auto B to manual
ROG:
UselessForce:
Regards what I’ve quoted though I wouldn’t have thought so, as far as I’m aware lower categories can not upgrade higher categories in any way but vice versa and they can. Sure Rog or Pete will be along with their expert knowledge to straighten us all out for sure though.Manual B can upgrade auto C etc to manual
Manual C can upgrade auto B to manual
Excellent thanks rog, another new thing learnt today look. Carry on like this and I should be very knowledgeable by the time I retire! 
No problem mastering gears/clutch in an LGV. Many years ago I used to teach total non-drivers on artics. My word, how things have changed!!
Pete
take it in a 12t which won’t be much bigger than the 7.5s you will encounter
Not always the case though. Our C1 training vehicle is no bigger than a Transit. But it’s 5 tonne gross so happily qualifies for a C1 licence.
Pete
Peter Smythe:
No problem mastering gears/clutch in an LGV. Many years ago I used to teach total non-drivers on artics. My word, how things have changed!!Pete
Sounds interesting, would of loved to experienced that! 
Sounds interesting, would of loved to experienced that!
Did it for years - and not just odd ones. Also a couple of years on a London Transport contract training non drivers on double deck buses with crash gear boxes and vacuum brakes. But now I’m really showing my age!
Pete